1. Field of the Invention
This invention relates to a gas lighter ignitable upon depression of an actuating means and, more particularly to a lighter with a safety device which remains deactivated by the engagement of a resilient member with an actuating means but can be activated by rendering the resilient member deformed.
2. Description of the Prior Art
Though a gas lighter is a convenient tool which can easily be ignited by the depression of the service end of an actuating lever, it can be a safety hazard for those who, like children, are unfamiliar with the proper use of the lighter. In addition, the lighter may be ignited by the unintentional depression of the service end happenly upon contact with stuffs.
In response to the demands for a gas lighter which is improved in safety in such a manner that inadvertent ignition by those who are unfamiliar with the proper use of the lighter can surely be prevented and the unintentional ignition can be prevented, child resistant gas lighters with several types of safety devices have already been known. Most of the safety devices built into these child resistant gas lighters have a lock mechanism which prevents depression of the actuating lever and which must be released to allow the actuating lever to be depressed. However, any of the conventional-type child resistant gas lighters will have drawbacks in their usage and thus it is desirable that the gas lighter be improved for practical use.
For instance, as disclosed in U.S. Pat. Nos. 4,859,172, 4,786,248, and 4,784,602 and Japanese Utility Model Publication No. 3(1991)-35971, any one of the disclosed safety devices is provided with a lock member for deterring depression of the actuating lever. Since the lock member is manually movable between a locked position and a released position, the lock member tends to stay at the released position without a manual recovery from the released position to the initial position after the use of the lighter, whereby the safety device remains unlocked. Leaving the lock member at the released position permits the actuating lever to be depressed, rendering the safety device inoperable. Specifically then, to ensure safety, the existing safety devices always require a manual re-locking operation after the use of the lighter with the lock mechanism unlocked, and hence there were expected further improvements of the lock mechanism in terms of safety.
To solve the drawbacks set forth above, there have been proposed, as a safety device having a lock member to impede the depression of the actuating lever, safety devices with what is called an auto-return function wherein the lock member automatically returns to the locked position in response to the ignition operation after the lock member has been manually moved to the released position. U.S. Pat. Nos. 5,002,482, and 3,898,031, and Japanese Unexamined Patent Publication No. 3(1991)-25215, for instance, disclose such safety devices as having the autoreturn function which allows automatic return of the lock member to the locked position in response to the ignition operation. With these safety devices, however, releasing the lock mechanism is only achieved by the motion of a finger along an L-shaped path, thereby resulting in the lock mechanism being inferior, in terms of operability, in the ease of releasing the lock member such that a lighter of this type generally requires operation with a single finger, such as a thumb, thus leading to different results depending on the users. Therefore, safety devices of this type can be said to be disadvantageous in practical use. Further, the operation of these safety devices is unreliable because of a probability that the lock member will return to the locked position by its own reactive force which is due to the resilience of the material constituting the lock member.
Furthermore, there have been proposed safety devices wherein the lock member is released by the motion of a finger not along the L-shaped path, but along a simple linear path, but any of those have drawbacks in practical use. The safety device as disclosed in Japanese Patent Publication of Translated Version (PCT) No. 3(1991)-501647, for instance is provided with an automatic return function wherein the part of a lock member being composed of a spring is moved along an arcuate path to the released position and held there, then it automatically returns to the locked position in response to the ignition operation. In this type of safety device, the arrangement for guiding the release of the spring-like lock member is not satisfactory, and accordingly the lock member cannot be steadily released. This adversely affects the ease of releasing the lock mechanism in the gas lighter, which is generally operated with a single finger, and, as with the preceding example, the resulting operations will be different depending on the users. Since the lock member itself is formed of a spring, the lock member may become deformed and cause failure of the lock mechanism after repeated use of the lighter.
In the safety device disclosed in U.S. Pat. No. 4,832,596, the lock member is moved to the released position along a linear path, but automatically returns to the initial position unless it is held at the locked position with a finger other than the one used for actuating the ignition mechanism. Thus, the lock member cannot steadily be released. This adversely affects the ease of releasing the lock mechanism in a gas lighter, which is generally operated with a single finger, e.g. the thumb, and, as with the preceding examples, leads to different operational results depending on the users.
In order to overcome such problems, there has been proposed an autoreturn safety device in which the lock member is moved along a linear path to the released position, thereby facilitating the release of the lock mechanism, and at the same time, the lock mechanism can be held in the released position with the finger which actuates the ignition mechanism, thus not requiring another finger. However, the safety device also has drawbacks in its practical use. That is, in the safety device disclosed in Japanese Unexamined Utility Model Publication No. 1(1989)-178456, the lock member is incorporated in the actuating lever which is actuated to ignite the lighter and the actuating lever can be operated with use of the same finger that has been used in releasing the lock member, i.e. the thumb which is generally used in an ignition operation, thus facilitating the releasing operation. However, when the actuating lever is actuated with the same finger (usually the thumb) which previously moved the lock member to the released position, the lock member may inadvertently be released from the thumb and may return to the locked position. Accordingly, also in this safety device, the lock member cannot be steadily released. This adversely affects the ease of releasing the lock mechanism in the gas lighter, which is generally operated with a single finger, e.g. the thumb, and, as with the preceding examples, this leads to different operational results depending on the users.
As can be seen from the description above, any one of the existing child resistant safety devices has drawbacks in practical use, and hence there has been a demand for a child resistant safety device which is improved in both safety and operability.
Further, in manufacturing gas lighters with such a safety device, it is required to rationalize the assembling steps, to improve assembling accuracy, thereby further enhancing the handling of the safety device, and to reduce the manufacturing cost.